Oil-poor switch with oil flow perpendicular to direction of movement of switch contact



4, 1964 w. HOFMANN 3,143,624

OIL-POOR SWITCH WITH on. FLOW PERPENDICULAR TO DIRECTION OF MOVEMENT OFSWITCH CONTACT Filed Dec. 11, 1961 2 Sheets-Sheet 1 ll 1-- a 1:: 3\ 5 II3 3 v 4 q mama-.9?

INVENTOR Werner Ho-Fmann ATTORNEYS 4, 1964 w. HOFMANN 3,143,624

OIL-POOR SWITCH WITH OIL FLOW PERPENDICULAR T0 DIRECTION OF MOVEMENT OFSWITCH CONTACT Filed Dec. 11. 1961 2 Sheets-Sheet 2 INVENTOR Werner-Hofmmnn ATTORNEYS United States Patent OKs-POOR SWITCH WITH GIL FLOWPERPENDKI- ULAR T0 DIRECTION (IF MOVEMENT 0F SWITCH CONTACT WernerHofrnann, Wettingen, Switzerland, assignor to Aktiengesellschaft Brown,Boveri 8: Cie, Baden, Switzerland, a joint-stock company Filed Dec. 11,1961, Ser. No. 158,222 Claims priority, application Switzerland Dec. 13,1960- 3 Ciaims. ((31. 200-150) This invention relates in general toelectrical switches and more particularly to those switches of theso-called oilpoor type wherein oil is fed perpendicularly to thedirection of movement of the movable contact part of the switch tofacilitate extinction of the are drawn between the contacts as they areseparated. Switches of this type include an extinguishing chamber forthe arc, this chamber being subdivided into a plurality of part chambersand into which the oil is pressed in laterally. In these part chambers,the oil is vaporized by the corresponding electric arc. Then a highpressure is developed which expedites the arc extinction and againestablishes a high value of voltage strength within the switching spaceto discourage re-ignition of the arc.

In the known constructions for this general type of switch, the oil isfed in from a single side and thereby the electric arc is pressed intothe opposite side. The gases are then passed out of the chamber again onthis side. The oil is here pressed out of the contact space, in which itwas located just before the beginning of the switch-oil, into theindividual parts of the extinguishing chamber, then vaporized in themand is then united again in an extingniishing medium collecting space.Movement of the oil is'caused by the movable contact part, in this casethe contact pin itself.

In the known switch constructions, each part chamber leads across acommon lead-off channel to the collecting space for the extinguishingmedium, in which the gases can again unite. However, with thisarrangement, there is the danger that through ionization of the gasesoutside of the point of contact, sparkovers can appear. This dangerarises in that the outlet opening lying immediately one behind the otheropen into the collecting space for the extinguishing medium. Thus, gasparts get together again which are connected also in the extinguishingchamber and thereby tend especially to re-ignition.

In order to avoid these disadvantages and, in addition, obtain betterutilization of the extinguishing chamber, the present invention providesan improved construction wherein the part chambers which collectivelyform the extinguishing chamber are connected with the space in which theswitch contacts are located by means of oppositely disposed oil feed-inchannels, and the collecting space is also connected with the partchambers by means of oppositely disposed oil lead-oft channels, theselead-in and lead-off channels being displaced relative to each other byapproxi- 'mately 90, and the oppositely disposed lead-in and leadoffchannels being arranged alternately on part chambers lying one behindthe other.

Different embodiments of the improved construction in accordance withthe invention are more particularly described hereinafter andillustrated in the attached drawings. In these drawings:

FIG. 1 is a view in central longitudinal section through theextinguishing chamber of the switch with the oppositely disposed lead-inchannels being cut;

FIG. 2 is a view similar to FIG. 1 but with the oppositely disposedlead-oh channels being cut;

FIG. 3 is a transverse section taken on line 33 of FIG. 1;

FIG. 4 is a transverse section taken on line 4-4 of FIG. 2;

FIG. 5 is a transverse section taken on line 55 of FIG. 1;

FIG. 6 is a vertical central section of a modified construction whereinone of the discs forming part of the extinguishing chamber is madeintegral with the cover disc part thereof; and

FIGS. 7, 8 and 9 are detail views showing the construction of thevarious discs employed in the assembly of the extinguishing chamber.

With reference now to the drawings, the improved electrical switch isseen to be comprised of a hollow cylinder 3 the interior of whichestablishes a pressure generating chamber 3a in which the stationarytulip contact member lot the switch is arranged. The movable pin contact2 which is adapted to engage with and be disengaged from the tulipcontact 1 is shown in the switched-oh? position. The space within thehollow cylinder 3 is filled with oil which comes up to about the levelindicated by the line 11. This oil is passed through oppositelydisposed, 1ongitudinally extending lead-in channels 9, 9' into theextingushing chamber 12, through which passes the pin contact member 2,by way of superposed transverse connecting channels 4, 5, 6 and 7. Thetransverse channels 4 and 6 communicate with the right feed-in channel9, and the channels 5 and 7 communicate with the left feed-in channel9'. The oil is thus alternately pressed out of channel 9 into channel 4,then out of channel 9' into channel 5, then again out of channel 9 intochannel 6, and finally out of channel 9' into channel 7. An even largernumber of superposed transverse channels can be provided if desired.

FIG. 2 illustrates the manner in which the vaporized oil is led ofli.From transverse channel 4, the oil vapor flows to the left into lead-01fchannel 10'. From the transverse channel 5, the vapor flows to the rightinto lead-off channel 10. Similarly, oil vapor flows from transversechannel 6 into channel 10' and from transverse channel 7 into channel10. Thus, here too the oil vapor passes alternately from transversechannels following one another into the lead-off channels 10, 10'. Theselatter lead into the collectingchamber 8 and it will be apparent that are-ignition or spark-over is practically eliminated since the channelsopen on opposite sides of the arrangement.

The oppositely disposed feed-in channels 9 and 9' and the oppositelydisposed lead-off channels 10 and 10' on the other side are displacedrelative to each other by This is shown by a cross section throughchannel 4 as viewed in FIG. 3. Out of the feed-in channel 9 which nowlies perpendicular to the plane of the drawing, the oil passes into thetransverse channel 4, is there vaporized by the electric arc drawnbetween contacts 1 and 2, and then passes into the leadoff channel It).The transverse channel 6 is designed identically with transverse channel4. Transverse channels 5 and 7 are shifted by so that as to them aconnection exists to the channels 9' and It across the transversechannels.

In order to separate the transverse channels 4-7 from each other, coverdiscs are provided as shown in FIG. 4. The transverse channels are alsoestablished in discs and hence, each channel is thus formed by a channeldisc and a cover disc. The disc providing transverse channel 4 isdenoted in FIG. 3 by 4' and similarly the discs correlated to the othertransverse channels 57 are denoted in FIG. 1 by 5' to 7'. Dics 4' and 6are identical and have the same orientation in the assembly. Disc 5' hasthe same structure as discs 4' and 6' but is displaced by an angle of180 relative to the latter two discs in the assembly. Disc 7' as shownin FIG. 7 is similar to discs 4' to 6 but lacks any aperture that wouldregister with the channel 9. The cover disc shown in FIG. 4 isdesignated 13. FIGS. 1 and 2 show three of these discs 13 at the upperpart of the assembly. Discs 13' and 13 at the lower part of the assemblyare detailed in FIGS. 8 and 9.

Thus, as seen in FIG. 3, each transverse channel disc, such as the disc4 depicted in this view, includes an armate passageway extending forapproximately 90 of arc and which includes a portion through which themovable contact 2 passes. The ends of the passageway terminaterespectively in alignment with a lead-in channel, in this case channel9, and a lead-off channel, in this case channel 10. Disc 4' alsoincludes an aperture therethrough forming, in this case, part of theopposite lead-off channel 19 and another aperture therethrough forming,in this case, part of the opposite lead-in channel 9'. Disc 5' isarranged in the stack so that its arcuate passageway is displaced 180from that of disc 4' so that the opposite ends thereof terminate inalignment respectively with leadin channel 9' and lead-off channel 10.The two other apertures therethrough would then form part of theopposite lead-off channel and lead-in channel 9.

Each cover disc 13 placed between the discs 4 and 5, and between 5' and6', includes a central aperture 12 forming part of the extinguishingchamber 12 through which the contact pin 2 passes, a pair of oppositelydisposed apertures forming part of the feed-in channels 9, 9' and a.pair of oppositely disposed apertures forming part of the leadoffchannels 10, 10'. Cover discs 13 shown in FIG. 8 is similar to disc 13but omits any aperture corresponding to channel 9. Cover disc 13", shownin FIG. 9 has only the apertures corresponding to channels 10, 10' andaperture 12'.

The contact space, as shown in FIG. 5 is designed to have an ovalconfiguration so that the lead-off channels lie in the walls of thecontact chamber until they reach the oil collecting chamber 8.

In a modified construction as shown in FIG. 6, it is also possible tocombine each transverse channel disc with a cover disc therefor into asingle integrated structure rather than have two disc elements assembledin face-toof a stack of transverse channel discs alternating with coverdiscs, or a stack of discs incorporating both the transverse channel andits cover.

I claim:

1. In an oil-poor switch, the combination comprising a housing includingan oil-filled pressure generating chamber containing a stationarycontact member and a pin contact member movable in a vertically downwarddirection to disengage itself from said stationary contact member, saidpin contact member being arranged to pass downwardly through an arcextinguishing device in said pressure generating chamber and which isconstituted by a stack of superposed discs including a central openingextending longitudinally therethrough in alignment with said stationarycontact member and through which said pin contact member passes, saidstack of discs including also a pair of oppositely disposedlongitudinally extending feed-in channels for the oil and a pair ofoppositely disposed longitudinally extending lead-off channels for theoil, said feedin and lead-off channels being displaced relative to eachother by 90, said feed-in and lead-oil? channels being alternatelyconnected with each other by transversely extending channels in saiddiscs intersecting said central opening such that the are drawn betweensaid stationary and pin contact members is extended to the right andleft in alternation in said transverse channels from said centralopening, and an oil collection chamber located within said housing abovesaid pressure generating chamber and which communicates with saidlead-off channels.

face relation. Such an integrated structure would have a cross sectionas shown in FIG. 6.

The operation of the improved arc extinguisher arrangement is such thatthe electric arc will be extended to the left in the transverse channels4 and 6, and to the right in transverse channels 5 and 7 as detailed inFIG. 2, the path of the are being shown by the zig-zag line 14. Therebyis achieved an extension 'on both sides. In addition, a completeseparation of the rising gases has been made possible. The advantage ofthe arrangement is a better separation of the rising electric arc gases,better utilization on both sides of the extinguishing chamber, and aconstructively simple production of the extinguishing chamber composed2. An oil-poor switch as defined in claim 1 wherein said discscontaining said transverse channels are separated from one another bydiscs which serve to cover said transverse channels, said cover discsbeing'provided with oppositely disposed apertures in alignment with andwhich form part of said oppositely disposed feed-in and lead-offchannels, and a central aperture forming part of the open ing throughwhich said pin contact member passes.

3. An oil-poor switch as defined in claim 1 wherein each said discincludes an integral cover element for its transverse channel.

References Cited in the file of this patent UNITED STATES PATENTS2,067,648 Reher Jan. 12, 1937 2,412,857 Baker Dec. 17, 1946 2,762,890Taylor et al Sept. 11, 1956 2,909,633 Umphrey Oct, 20, 1959 FOREIGNPATENTS 94,950 Norway Sept. 12, 1959

1. IN AN OIL-POOR SWITCH, THE COMBINATION COMPRISING A HOUSING INCLUDINGAN OIL-FILLED PRESSURE GENERATING CHAMBER CONTAINING A STATIONARYCONTACT MEMBER AND A PIN CONTACT MEMBER MOVABLE IN A VERTICALLY DOWNWARDDIRECTION TO DISENGAGE ITSELF FROM SAID STATIONARY CONTACT MEMBER, SAIDPIN CONTACT MEMBER BEING ARRANGED TO PASS DOWNWARDLY THROUGH AN ARCEXTINGUISHING DEVICE IN SAID PRESSURE GENERATING CHAMBER AND WHICH ISCONSTITUTED BY A STACK OF SUPERPOSED DISCS INCLUDING A CENTRAL OPENINGEXTENDING LONGITUDINALLY THERETHROUGH IN ALIGNMENT WITH SAID STATIONARYCONTACT MEMBER AND THROUGH WHICH SAID PIN CONTACT MEMBER PASSES, SAIDSTACK OF DISCS INCLUDING ALSO A PAIR OF OPPOSITELY DISPOSEDLONGITUDINALLY EXTENDING FEED-IN CHANNELS FOR THE OIL AND A PAIR OFOPPOSITELY DISPOSED LONGITUDINALLY EXTENDING LEAD-OFF CHANNELS FOR THEOIL, SAID FEEDIN AND LEAD-OFF CHANNELS BEING DISPLACED RELATIVE TO EACHOTHER BY 90*, SAID FEED-IN AND LEAD-OFF CHANNELS BEING ALTERNATELYCONNECTED WITH EACH OTHER BY TRANSVERSELY EXTENDING CHANNELS IN SAIDDISCS INTERSECTING SAID CENTRAL OPENING SUCH THAT THE ARC DRAWN BETWEENSAID STATIONARY AND PIN CONTACT MEMBERS IS EXTENDED TO THE RIGHT ANDLEFT IN ALTERNATION IN SAID TRANSVERSE CHANNELS FROM SAID CENTRALOPENING, AND AN OIL COLLECTION CHAMBER LOCATED WITHIN SAID HOUSING ABOVESAID PRESSURE GENERATING CHAMBER AND WHICH COMMUNICATES WITH SAIDLEAD-OFF CHANNELS.